Issue with iCloud drive app

I am using ios 9 on my iphone 6s. I kept iCould Drive option ON in settings to take backup of note, calendar etc. and I took backup as well couple of times. From iCould setting page, i can see available storage as 3.8GB which means 1.2GB is already backed up.

Now if i check files using iCloud Drive App, i doesnt show any data. At bottom, it says 0 items, 3.76 GB available on iCloud. Not sure why iCloud Drive apps not showing any data.

Any thought ?

Thx